Identifying key volatile organic compounds (VOCs) that help slugs locate host plants can enhance eco-friendly slug management. We used sequential solvent extraction of Ginkgo biloba seed exocarps and tested the extracts for attractiveness. Slugs preferred chloroform and ethanol extracts, and, to a lesser extent, n-hexane extracts, whereas ethyl acetate and acetone extracts were not attractive. The attractiveness of an extract to slugs was positively correlated with the richness of VOCs. We screened nine dominant VOCs and found that γ-octalactone and tetradecane were highly attractive to slugs, even at low concentrations. Butyl caprate attracted slugs at low to medium concentrations, while pentadecane was attractive at medium to high concentrations. Ethyl salicylate and trans-2-undecenal were attractive only at high concentrations. Four VOC mixtures were highly attractive under both laboratory and field conditions. These findings indicate that plant volatile-based baits are effective for trapping large numbers of slugs, offering valuable insights for the development of botanical attractants.

Tobacco brown spot disease, caused by Alternaria alternata, poses a significant threat to crop production. Traditional control methods, particularly chemical fungicides, have raised concerns about environmental impact and resistance. Although our previous research has shown that volatile compounds produced by Bacillus velezensis EM-1 can effectively suppress A. alternata, the specific antifungal compounds and their mechanisms remain unclear. In this study, exposure to the volatiles from strain EM-1 significantly inhibited the mycelial growth and spore germination of A. alternata, with 2-nonanol identified as the most potent antifungal compound. Fumigation experiments revealed that 2-nonanol exhibited strong dose-dependent toxicity, with an EC50 of 0.1055 μL/cm3 and a minimum inhibitory concentration of 0.2166 μL/cm3. In vivo experiments on tobacco leaves confirmed that 2-nonanol effectively reduced tobacco brown spot disease incidence and slowed lesion expansion. Transcriptome analysis indicated that 2-nonanol downregulated the expression of genes encoding D-glucose synthesis in carbon metabolism, which limited energy acquisition by A. alternata. Moreover, the expression of antioxidant enzymes, including superoxide dismutase (SOD) and catalase (CAT), was markedly suppressed by 2-nonanol, thereby exacerbating cellular damage induced by oxidative stress. These findings suggest that 2-nonanol holds potential as a biocontrol agent for managing tobacco brown spot disease, underscoring the promising role of volatile organic compounds (VOCs) in the development of environmentally friendly biocontrol products.

Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) is widely used in aphid biological control, and lowtemperature storage helps expand its population. Nonetheless, low-temperature effects on A. aphidimyza are unknown. A. aphidimyza pupae were exposed to three cold storage methods lasting 10, 20, and 30 days, respectively: storing at 7 degrees C for 4 h then 5 degrees C for 20 h (T1); storing at 9 degrees C for 4 h then 5 degrees C for 20 h (T2); and storing at 5 degrees C for 24 h (T3). The emergence rate under variable low-temperature storage (T1: 81.98%; T2: 81.28%) was significantly higher than that under constant low-temperature storage (T3: 74.98%). Additionally, the emergence rate decreased markedly with prolonged refrigeration time. Egg production at all three refrigeration temperatures declined significantly compared to the control treatment. It is noteworthy that lowtemperature storage can significantly prolong the development time of offspring larvae without affecting the overall developmental period of the offspring. After comparing the content of cold-resistant substances in pupae under different low-temperature storage, the total sugar, glycerol, and trehalose increased with an extended storage time. The lifetime feeding capacity of A. aphidimyza offspring larvae on Myzus persicae (Sulzer) improved after cold storage. The functional response curve was aligned with the Holling II model. Compared to the control treatment, both T1, T2, and T3 improved the search ability of 3rd-instar larvae in the offspring after 20 and 30 days of refrigeration. Our study indicated that cold storage of A. aphidimyza can extend offspring larval development period and improve its predation ability.

Abstract Aspergillus genus is a key component in fermentation and food processing. However, sterigmatocystin (STE)—a mycotoxin produced by several species of Aspergillus—limits the use of some Aspergillus species (such as Aspergillus versicolor, Aspergillus inflatus, and Aspergillus parasiticus) because of its toxicity and carcinogenicity. Here, we engineered an STE‐free Aspergillus versicolor strain based on genome mining techniques. We sequenced and assembled the Aspergillus versicolor D5 genome (34.52 Mb), in which we identified 16 scaffolds and 54 biosynthetic gene clusters (BGCs). We silenced cytochrome P450 coding genes STC17 and STC27 by insertional inactivation. The production of STE in the Δstc17 mutant strain was increased by 282% but no STE was detected in the Δstc27 mutant. Metabolites of Δstc27 mutant exhibited growth‐promoting effect on plants. Our study makes significant progress in improving the application of some Aspergillus strains by restricting their production of toxic and carcinogenic compounds.

【Objective】The effect of different combined application rates of organic fertilizer and chemical fertilizer on nitrogen supply capacity and greenhouse gas emission of tobacco-growing soil is explored, which provides scientific guide for improvement of yield and quality of tobacco leaves, adjustment and perfection of fertilization method.【Method】Rapeseed cake（RC）, pig manure（PM）, carbon-based organic fertilizer（BOF） and peanut straw（PS） were selected as the test organic materials, and the nitrogen substitution ratio of chemical fertilizers was set at two levels, 30% and 50% respectively.Through the pot experiment, the differences in agronomic characteristics, biomass, soil mineral nitrogen content, soil organic carbon content, greenhouse gas emissions of flue-cured tobacco between treatments were compared.【Result】Compared with chemical fertilizer treatment（CK）, except for BOF treatment, other combined organic fertilizer treatments all reduced the mineral nitrogen content of the soil by 22.9%-57.84%（resettling growth stage）, 4.97%-66.04%（prosperous growth period）, 25.59%-83.82%（budding period）, 33.58%-68.90%（mature period）.Except for peanut straw treatment, other organic fertilizer treatments did not significantly reduce the biomass of flue-cured tobacco roots, stems and leaves.Only the combined application of pig manure and peanut straw treatment significantly increased CO 2 emissions by 23.74%-33.40% and 61.75%-87.54% respectively.Only when the proportion of organic materials was 50%, the N 2 O emission was significantly increased, and the increase was 7.73-21.89 times.The combined application of organic materials increased the total nitrogen content of the soil by 1.56%-20.68%, and also significantly increased the total soil carbon content by 2.77%-16.63%.Rapeseed cake treatment significantly reduced soil C/N ratio, while peanut straw treatment significantly increased soil C/N ratio, but pig manure and carbon-based organic fertilizer treatment had no significant effect on soil C/N ratio.【Conclusion】Comprehensive comparison showed that carbon-based organic fertilizer was suitable for tobacco planting.From the aspects of nitrogen supply capacity of tobacco soil, biomass of tobacco plant and N 2 O emission, the proportion of organic materials should be 30%, and shouldnot be higher than 50%.In order to maintain the carbon and nitrogen balance of tobacco planting soil, rapeseed cake with low C/N ratio and peanut straw with high C/N ratio should not be applied separately and continuously.

为了开发新型、安全、高效的天然产物除草剂,采用倒置"W"九点取样法和三层三级目测法对贵州省遵义市道真县和余庆县烟田杂草危害情况进行调查,明确优势杂草种类和防治需求;对具有显著除双子叶杂草活性的海洋杂色曲霉Aspergillus versicolor D5进行发酵提取,明确活性成分及含量;进而采用茎叶喷雾法评价D5发酵提取物的田间除草效果.结果表明:(1)道真烟田中共有9科15种杂草发生,以双子叶菊科种类最多,以苋科相对多度值最高,占比高达84.2％,是优势杂草;余庆烟田中共有16科39种杂草发生,危害度为Ⅰ级、Ⅱ级、Ⅲ级的杂草分别有29种、9种、1种,危害度达到Ⅲ级的为双子叶杂草蓼;(2)海洋杂色曲霉D5发酵提取物在10％乙酸乙酯-石油醚洗脱后,采用100％乙酸乙酯洗脱,浓缩后活性物质基本无损失,包含柄曲霉素ST(14.6％)和二氢柄曲霉素DHST(0.4％);(3)田间小区试验发现,D5发酵提取物在低施药量(675 g/hm2)下具有显著的除草作用,特别是对双子叶杂草具有明显的抑制效果,以对玄参科杂草婆婆纳Veronica didyma最为显著,鲜质量防效达到61.4％;同时,对狗尾草Setaria viridis和打碗花Calystegia hederacea的鲜质量防效亦达到50％以上.由此可见,海洋杂色曲霉D5发酵提取物抗草谱广,对双子叶杂草除草作用明显,具有开发成为天然产物除草剂的潜力.

Sterigmatocystin (STE) is a common hepatotoxic and nephrotoxic contaminant in cereals, however, its phytotoxicity and mechanisms are poorly understood. Here, the phytotoxic mechanisms of STE were investigated via the metabolomics of Amaranthus retroflexus L. A total of 140 and 113 differential metabolites were detected in the leaves and stems, respectively, among which amino acids, lipids, and phenolic compounds were significantly perturbed. Valine, leucine, isoleucine, and lysine biosynthesis were affected by STE. These metabolic responses revealed that STE might be toxic to plants by altering the plasma membrane and inducing oxidative damage, which was verified by measuring the relative electrical conductivity and quantification of reactive oxygen species. The elevated amino acids, as well as the decreased of D-sedoheptuiose-7-phosphate indicated increased proteolysis and carbohydrate metabolism restriction. Furthermore, the IAA level also decreased. This study provides a better understanding of the impacts of STE on the public health, environment and food security.

[目的]我国烤烟上部烟叶仍存在因烟碱含量较高而影响其品质的问题.向土壤中添加有效碳源可刺激微生物同化作用,进而能够调控土壤中有效氮含量.因此,本研究尝试利用外源碳降低烤烟上部叶全氮和烟碱含量.[方法]设置盆栽试验,烤烟品种为NC55,供试外源碳为葡萄糖(G)和木屑(S).试验设9个处理:在烤烟移栽后第90天,分别向植烟土壤中添加葡萄糖C 2000 mg/kg(G2)、5000 mg/kg(G5);在移栽后第90和120天依次添加葡萄糖C 2000 mg/kg和10000 mg/kg(G2+G10),和依次添加葡萄糖C 5000 mg/kg和10000 mg/kg(G5+G10);在移栽后第90天分别添加木屑C 2000 mg/kg(S2)和5000 mg/kg(S5);在移栽后第90和120天依次添加木屑C 2000 mg/kg和葡萄糖C 10000 mg/kg(S2+G10),和依次添加木屑C 5000 mg/kg和葡萄糖C 10000 mg/kg处理(S5+G10);对照(CK)为常规施肥处理,在移栽后不添加外源碳.比较不同处理土壤氮素水平、烟叶全氮和烟碱含量.[结果]烤烟生长后期添加外源碳可明显降低植烟土壤氮素供应,降低幅度随外源碳添加量的增加而增大,添加二次比添加一次效果更明显,葡萄糖和木屑配合添加较单纯添加葡萄糖更有效.添加二次可降低上部叶的烟碱和全氮含量分别达0.62～1.40个百分点和0.71～1.22个百分点,比添加一次效果更为明显.[结论]烤烟生长后期在土壤中分别添加一定量的葡萄糖和木屑,能有效调节土壤碳氮比,抑制烤烟吸收过量的氮素,进而降低烤烟上部叶烟碱和全氮含量,提高烟叶品质.

In order to examine the exogenous situation of heavy metals in tobacco growing areas of Zunyi City,irrigation water samples (n=572) and organic fertilizer samples(n=21) were collected from the main tobacco growing areas.The concentration of As,Cd,Cr and Pb were investigated and compared with the national standards.The results showed that the concentration of As,Cd,Cr and Pb in the irrigation water were 0～71％,0～2.9％,0～6.6％ and 0～8.5％ of the national standard respectively.The concentration of As,Cd,Cr and Pb in fertilizers were 3.87％～64.1％,2.33％～74.7％,6.53％～38.1％ and 10.9％～59.2％ of the national standard respectively.The concentration of heavy metals in irrigation water and organic fertilizer in the main tobacco growing areas of Zunyi City is at the safe level.